The aims of the Tissue Banking and Molecular Assessment Core are to:[unreadable] 1. Receive, process, store, and retrieve samples from children and adults with acute lymphoblastic leukemia[unreadable] and appropriately distribute material to the scientific and clinical projects within the Program.[unreadable] 2. Perform real time quantitative polymerase chain reaction assays using as markers the unique IgH and TCR[unreadable] rearrangements identified in the diagnostic patient samples.[unreadable] Core C will work to obtain peripheral blood and bone marrow samples,[unreadable] isolate the mononuclear cell fraction and cryopreserve cells, RNA and DNA from tumor samples. The Core[unreadable] will distribute these samples to the Projects as required and will prioritize the use of samples in which cell[unreadable] numbers are limiting. This will allow for distribution of the most appropriate samples to each Project to[unreadable] achieve the scientific aims of Projects 1, Project 3, Project 4, Project 5, and Project 6. The Core will[unreadable] provide molecular biologic analysis of immunoglobulin heavy chain (IgH) and T cell receptor (TCR) gene[unreadable] rearrangements in diagnostic samples and perform quantitative polymerase chain reaction assays in post[unreadable] treatment samples using as markers these patient specific gene rearrangements. The goal is to assess the[unreadable] dynamics of the eradication of minimal residual disease and identify patients at sufficiently high risk of relapse[unreadable] to be candidates for experimental treatment approaches in Project 6, using the targets identified within[unreadable] Projects 1, 3, 4 and 5. The Core is essential to achieve the full translational potential of this Program.